Alstom MiCOM P846, Техническое руководство

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Operation P846/EN OP/D
MiCOM P846
(OP) 5-17
OP
−
Circuit Breaker (CB) is defective
ormally
open / normally closed output contact can be assigned to this function via the programmable
during normal
ROL relay menu there is a setting called ‘CB Status Input’.
owing options:
None
52A
52B 3 pole
52A
52A
52B
52A & 52B 1 pole
Should both sets of contacts be closed, only one of the following two conditions would apply:
−
Auxiliary contacts / wiring defective
If any of the above conditions exist, an alarm will be issued after a 5s time delay. A n
scheme logic (PSL). The time delay is set to avoid unwanted operation
switching duties.
In the CB CONT column of the
This cell can be set at one of the foll
3 pole
& 52B 3 pole
1 pole
1 pole
Selection of the inputs used for CB status is user definable in the CB Status Input cell under
nu. The inputs used to determine the circuit breakers status can be either
ntacts for single or three pole and for one circuit breaker or for two circuit
nputs via the PSL.
Auxiliary Contact Position CB State Detected Action
the CB control me
52a and/or 52b co
breakers in the case of the P846.
Where ‘None’ is selected no CB status will be available. This will directly affect any function
within the relay that requires this signal, for example CB control, auto-reclose, etc. Where
only 52A is used on its own then the relay will assume a 52B signal from the absence of the
52A signal. Circuit breaker status information will be available in this case but no
discrepancy alarm will be available. The above is also true where only a 52B is used. If
both 52A and 52B are used then status information will be available and in addition a
discrepancy alarm will be possible, according to the following table. 52A and 52B inputs are
assigned to relay opto-isolated i
52A 52B
Open Closed Breaker Open Circuit breaker healthy
Closed Open Breaker Closed Circuit breaker healthy
Closed Closed CB Failure Alarm raised if the condition
persists for greater than 5s
Open Open State Unknown Alarm raised if the condition
persists for greater than 5s
Table 1.
Where single pole tripping is used (available on certain relays only) then an open breaker
condition will only be given if all three phases indicate and open condition. Similarly for a
closed breaker condition indication that all three phases are closed must be given. For
single pole tripping applications 52A-a, 52A-b and 52A-c and/or 52B-a, 52B-b and 52B-c
inputs should be used.
In the case of the P846 two circuit breakers are monitored. If inputs relevant to each of the
circuit breaker’s (CB1 and CB2) are available to the relay via the opto isolated inputs it will
be able to determine the state of each circuit breaker.